The present invention relates to a matrix display apparatus. The present invention is effective for using matrix displays, such as liquid-crystal device (LCD) panels, as High-Vision resolution display devices.
It is expected that new television systems, such as digital satellite broadcast systems and digital terrestrial broadcast systems will take place of the conventional NTSC and MUSE systems in near future across the 21st century.
In the NTSC system, a 480 lines interlaced scanning system has been adopted. In the Hi-Vision broadcast systems adopting the MUSE system, a total of 1125 scan lines are used, while 1035 scan lines present on an actually-visible display screen. Therefore, conventional monitors and television (TV) receivers were enough to be compatible to a total of 1125 scan lines and the actually-visible 1035 scan lines.
Incidentally, in plans of digital broadcasts, such as the DTV system decided in the United States and similar systems on diagram boards in the world, a variety of scanning systems are proposed. For example, a 480 lines interlaced scanning system (hereinafter referred to 480i), a 480 lines progressive scanning system (hereinafter referred to 480p), a 1080 lines interlaced scanning system (hereinafter referred to 1080i) and a 720 lines progressive scanning system (hereinafter referred to 720p) have been planned.
Therefore, it is needed that the monitors and the TV receivers is compatible to not only the conventional NTSC and MUSE system broadcasts, but also to a variety of scanning systems.
Referring now to FIG. 12, a construction of conventional TV receivers will be described.
In FIG. 12 a DTV (digital television) demodulator 11 demodulates digital color TV signals from an OFDM (Orthogonal Frequency Division Multiplexing)-modulation digital color TV broadcast signal received through an antenna, such as a parabola antenna. A DTV decoder 12 decodes MPEG-2 encoded signals from the DTV demodulator 11. An analog-to-digital (A/D) converter 13 converts analog signals of 1080i scan format, or analog signals of 1035i scan format into 10-bit order digital signals. Here, color TV signals definitely consist of three-color signals, i.e., a luminance signal (Y) and two color-difference signals (Pr, Pb). Thus the A/D converter 13 is actually comprised of three units (not shown). A 1080i/720p converter 14 converts 1080i scan format signals to 720p scan format signals by alternatively storing the odd and even fields each consisting of 540 scan lines into a frame memory, and applying a motion-adaptive processing etc.
In this embodiment, although an exemplified conversion from mainly a 1080i format to a 720p format is described, the same goes for a conversion from a 1035i format to the 720p format. By the way, the conventional Hi-Vision system signal also utilizes a total number of 1125 lines the same as that of the digital TV system signal. Thus, by processing 45 lines of them as lines in a non-image area, i.e., a vertical retrace period, the same circuit configuration and operation can be applied to both of the Hi-Vision system and the digital TV system.
An analog-to-digital converter (A/D converter) 15 converts the 480i scan format or the 480p scan format from analog form to digital form. A 480i(p)/720p converter 16 converts the digital signals from the A/D converter 15 from a 480i(p) scan format to a 720p scan format. Wherein, 480i scan format signals are converted into 720p scan format signal while storing odd and even fields each consisting of 240 scan lines into a field memory and performing a motion-adaptive signal processing. On the other hand, 480p scan format signals are converted into the 720p scan format signals in every fields.
A selector 17 selects either the digital signals from the 1080i/720p converter 14 or the 480i(p)/720p converter 16. A D/A converter 18 converts the image signals selected by the selector 17 from digital form back to analog form. Since color displays require three signals, i.e., a luminance signal (Y signal) and two color-difference signals (Pr, Pb), the D/A converter 18 is actually comprised of three units (not shown).
An LCD driver 19 adequately processes the luminance signal Y and the color-difference signals Pr, Pb to drive an LCD panel 21. The LCD driver 19 comprises a matrix circuit for restoring three primary color signals R, G, B from the luminance signal Y and the color-difference signals Pr, Pb, a gamma correction circuit for correcting voltage-luminance characteristics curve of the LCD panel 21, a polarity alternator for alternating polarities of signals given to the LCD panel 21. Here, the alternate-driving of LCDs is performed for preventing deteriorations of LCDs caused by applying only one polarity signal to LCD panels.
An LCD controller 20 controls timings of enabling scan lines (rows) y1, y2, y3, . . . and data lines (columns) x1, x2, x3, . . . of the LCD panel 21 in synchronism with the drive signals supplied from the LCD driver 19. When the LCD panel 21 is of a low-cost and of a midrange resolution, 720 units of scan lines (rows) y1, y2, y3, . . . are vertically aligned, while 1280 units of data-lines (columns) x1, x2, x3, . . . are laterally aligned.
The LCD controller 20 deals with three drive signals associated to the luminance signal Y and the color-difference signals Pr, Pb. Thus the LCD controller 20 is actually comprised of three units (not shown). In the receiver, as shown in FIG. 12 the LCD panel 21 accepts three types of drive signals. The first drive signal originates from the 1080i scan format signal which is obtained by demodulating the DTV-modulation transmitting signal in the DTV demodulator 11 and then decoded in the DTV decoder 12. The second drive signal originates from the analog luminance signal and color-difference signals of the 1080i or the 1035i scan format which are supplied from conventional MUSE decoders or MUSE disc players to the A/D converter 13. The 1080i format signals associated to the first and the second drive signals are converted into the 720p scan format signal in the 1080i/720p converter 14. The third drive signal originates from the 480i or the 480p scan format signals such as the conventional NTSC signals supplied to the A/D converter 15 and then converted to the 720p scan format signal in the 480i(p)/720p converter 16.
Since all of the above-mentioned three drive signals are converted their formats into the 720p scan format before the LCD panel 21, if their scanning line signals are supplied one by one into the LCD panel 21 in their order, a correct image corresponding to the scan format conversion algorism is displayed on the LCD panel 21.
Although the A/D converter 13 can convert analog 1080i or 1035i scan format signals into 8-bit or 10-bit digital signals, it requires a very high sampling frequency of 75 MHz and also three units of expensive converters for the luminance signal Y and the color-difference signals Pr and Pb, respectively. Moreover, since separate type MUSE decoders and disc players are not presently in common, input terminals for the MUSE decoders and disc players are rarely used. Nevertheless, an equipment of three expensive A/D converters and their peripheral devices has caused the burden on great cost. If their costs could be suppressed sufficiently close to a price reasonable for customers, such an attempt of reducing costs can contribute for a proliferation of monitors and TV receivers compatible not only to the conventional NTSC and MUSE system broadcasts, but also to a variety of scanning systems.
With consideration for the above problems, the object of the present invention is to provide a matrix display apparatus to which analog signals can be directly supplied thus eliminating the need for expensive A/D and/or D/A converters, by devising driving schemes of the LCD panels.
To achieve the above objects, a matrix display apparatus according to a first aspect of the present invention includes, a display panel device provided with a plurality of data-lines and a plurality of scan-lines which are arranged in a matrix and a controller for controlling the display panel device, wherein the controller generates a write instruction signal, (i) for instructing an (axc3x97n+b)-th scanning line image signal of the first field image signal to be written on adjoining two scan-lines (a and b are constants; a greater than b; n is a zero or a positive integer), (ii) for instructing the other scanning line image signals of the first field image signal to be written on one of the scan-lines, (iii) for instructing an (axc3x97n+c)-th scanning line image signal of the second field image signal to be written on adjoining two scan-lines (c is a constant; a greater than c), and (iv) for instructing the other scanning line image signals of the second field image signal to be written on one of the scan-lines.
A matrix display apparatus according to a second aspect of the present invention includes, a display panel device provided with a plurality of data-lines and a plurality of scan-lines which are arranged in a matrix and a controller for controlling the display panel device, a data-driver for supplying an interlaced format image signal to the data-lines of the display panel device in accordance with a write instruction signal provided from the controller, and a scan-driver for shifting an active scan-line in the vertical direction of the display panel device in accordance with the line-shift instruction signal provided from the controller, wherein the controller generates a write instruction signal, (i) for instructing an (axc3x97n+b)-th scanning line image signal of the first field image signal to be written on adjoining two scan-lines, (ii) for instructing the other scanning line image signals of the first field image signal to be written on one of the scan-lines, (iii) for instructing an (axc3x97n+c)-th scanning line image signal of the second field image signal to be written on adjoining two scan-lines, and (iv) for instructing the other scanning line image signals of the second field image signal on one of the scan-lines.
A matrix display apparatus according to a third aspect of the present invention includes, a display panel device provided with a plurality of data-lines and a plurality of scan-lines which are arranged in a matrix, and a controller for controlling the display panel device, a data-driver for supplying the interlaced format image signal to the data-lines of the display panel device in accordance with a write instruction signal provided from the controller, a first scan-driver for shifting an odd-numbered active. scan-line in the vertical direction in accordance with the line-shift instruction signal provided from the controller, and a second scan-driver for shifting an even-numbered active scan-line one by one in the vertical direction in accordance with the line-shift instruction signal provided from the controller, wherein the controller generates a write instruction signal, (i) for instructing either of the first and second scan-drivers to supply the image signals of 3n-th and (3n+1)-th scanning line image signals of a 2k-th field (k is an arbitrary integer) to the display panel device, (ii) for instructing both of the first and second scan-drivers to supply the image signals of the (3n+1)-th scanning line image signals of the 2k-th field to the display panel device, (iii) for instructing both of the first and second scan-drivers to supply the image signals of a (3n+2)-th scanning line image signal of the 2k-th field to the display panel device, (iv) for instructing both of the first and second scan-drivers to supply the image signals of the 3n-th scanning line image signal of the 2k-th field to the display panel device, (v) for instructing either of the first and second scan-drivers to supply the image signals of the (3n+1)-th and (3n+2)-the scanning line image signals of the (2k+1)-th field to the display panel device, and (vi) for instructing either of the first and second scan-drivers to supply the image signals of the (3n+1)-th and (3n+2)-the scanning line image signals of the (2k+1)-th field to the display panel device.
Other than the features as those of the second and third aspects, a matrix display apparatus according to a fourth aspect of the present invention further includes, an LCD (liquid-crystal display) panel device and a polarity alternator for alternating the polarity of the image signal to be provided to the LCD panel device for every horizontal scanning line, wherein the polarity alternator (i) renders the image signals in 4m-th and (4m+3)-th (m is an arbitrary integer) fields to a first polarity and (ii) renders the image signal in (4m+1)-th and (4m+2)-th fields to a second polarity.
Other than the features as those of the second and third aspects, a matrix display apparatus according to a fifth aspect of the present invention further includes, an LCD (liquid-crystal display) panel device and a polarity alternator for alternating a polarity of the image signal to be supplied to the LCD panel device for every horizontal scanning line, wherein the polarity alternator (i) renders 3n-th and (3n+1)-th scanning line image signals in a 2k-th field to a first polarity, (ii) renders a (3n+2)-th scanning line image signal in the 2k-th field to a second polarity, (iii) renders the (3n+1)-th and (3n+2)-th scanning line image signals in a (2k+1)-th field to the second polarity, (iv) renders the 3n-th scanning line image signal in the (2k+1)-th field to the first polarity, and (iv) renders the 3n-th scanning line image signal in the (2k+1)-th field to the first polarity.
A matrix display apparatus according to a sixth aspect of the present invention includes, a display panel device provided with a plurality of data-lines and a plurality of scan-lines which are arranged in a matrix, and a controller for controlling the display panel device, a data-driver for supplying an interlaced format image signal to the data-lines of the display panel device in accordance with a write instruction signal supplied from the controller, and a scan-driver for shifting an active scan-line in the vertical direction of the display panel device in accordance with the line-shift instruction signal supplied from the controller, wherein the controller generates a control signal (i) for disabling the scan driver when an (axc3x97n+b)-th scanning line image signal is supplied in a 2k-th field and (ii) for disabling the scan driver when an (axc3x97n+c)-th scanning line image signal is supplied in a (2k+1)-th field.
A matrix display apparatus according to a seventh aspect of the present invention includes, a display panel device provided with a plurality of data-lines and a plurality of scan-lines which are arranged in a matrix, a controller for controlling the display panel device, a data-driver for supplying the interlaced format image signal to the data-lines of the display panel device in accordance with a write instruction signal supplied from the controller, a first scan-driver for shifting an odd-numbered active scan-line in the vertical direction in accordance with the line-shift instruction signal supplied from the controller, and a second scan-driver for shifting an even-numbered active scan-line one by one in the vertical direction in accordance with the line-shift instruction signal supplied from the controller, wherein the controller generates a control signal, for disabling the first and second scan drivers when an (axc3x97n+b)-th scanning line image signal is supplied in a 2k-th field, and for disabling the first and second scan drivers when an (axc3x97n+c)-th scanning line image signal is supplied in a (2k+1)-th field and for enabling the first and second scan drivers when scanning line image signal other than the (axc3x97n+c)-th scanning line image signal are supplied in the (2k+1)-th field.
According to the above-described schemes, it is able to display analog 1080i scan format signals without the need for expensive A/D and/or D/A converters and thus the cost of the matrix display apparatus is extensively reduced.
Additional objects and advantages of the present invention will be apparent to persons skilled in the art from a study of the following description and the accompanying drawings, which are hereby incorporated in and constitute a part of this specification.